#include "screens/dashboard/widgets/QuickTradeWidget.h"

#include "datahub/DataHub.h"
#include "datahub/DataHubMetaTypes.h"
#include "ui/theme/Theme.h"

#include <QFrame>
#include <QHBoxLayout>
#include <QMessageBox>

namespace fincept::screens::widgets {

static QString input_style(const QString& border_color = "") {
    QString bc = border_color.isEmpty() ? ui::colors::BORDER_MED() : border_color;
    return QString("QLineEdit { background: %1; color: %2; border: 1px solid %3; "
                   "font-size: 11px; padding: 4px 6px; }"
                   "QLineEdit:focus { border-color: %4; }")
        .arg(ui::colors::BG_BASE())
        .arg(ui::colors::TEXT_PRIMARY())
        .arg(bc)
        .arg(ui::colors::AMBER());
}

static QString combo_style() {
    return QString("QComboBox { background: %1; color: %2; border: 1px solid %3; "
                   "font-size: 11px; padding: 4px 6px; }"
                   "QComboBox::drop-down { border: none; width: 16px; }"
                   "QComboBox QAbstractItemView { background: %1; color: %2; border: 1px solid %3; }")
        .arg(ui::colors::BG_BASE())
        .arg(ui::colors::TEXT_PRIMARY())
        .arg(ui::colors::BORDER_MED());
}

QuickTradeWidget::QuickTradeWidget(QWidget* parent) : BaseWidget(tr("QUICK TRADE"), parent, ui::colors::AMBER()) {
    auto* vl = content_layout();
    vl->setContentsMargins(10, 10, 10, 10);
    vl->setSpacing(8);

    // ── Symbol search bar ──
    auto* search_row = new QWidget(this);
    auto* srl = new QHBoxLayout(search_row);
    srl->setContentsMargins(0, 0, 0, 0);
    srl->setSpacing(6);

    symbol_input_ = new QLineEdit;
    symbol_input_->setPlaceholderText(tr("Symbol (e.g. AAPL)"));
    symbol_input_->setText("AAPL");
    srl->addWidget(symbol_input_, 1);

    lookup_btn_ = new QPushButton(tr("LOOKUP"));
    srl->addWidget(lookup_btn_);
    vl->addWidget(search_row);

    // ── Quote display ──
    quote_card_ = new QWidget(this);
    auto* qcl = new QHBoxLayout(quote_card_);
    qcl->setContentsMargins(10, 8, 10, 8);
    qcl->setSpacing(12);

    auto* sym_col = new QVBoxLayout;
    sym_label_ = new QLabel("--");
    sym_col->addWidget(sym_label_);
    change_label_ = new QLabel("--");
    sym_col->addWidget(change_label_);
    qcl->addLayout(sym_col);

    qcl->addStretch();

    auto* price_col = new QVBoxLayout;
    price_col->setAlignment(Qt::AlignRight);
    price_label_ = new QLabel("--");
    price_label_->setAlignment(Qt::AlignRight);
    price_col->addWidget(price_label_);

    auto* bid_ask_row = new QHBoxLayout;
    bid_label_ = new QLabel(tr("BID --"));
    bid_ask_row->addWidget(bid_label_);
    bid_ask_row->addSpacing(8);
    ask_label_ = new QLabel(tr("ASK --"));
    bid_ask_row->addWidget(ask_label_);
    price_col->addLayout(bid_ask_row);
    qcl->addLayout(price_col);

    vl->addWidget(quote_card_);

    // ── Separator ──
    separator_ = new QFrame;
    separator_->setFixedHeight(1);
    vl->addWidget(separator_);

    // ── Order form ──
    // Side + Type row
    auto* st_row = new QHBoxLayout;
    st_row->setSpacing(6);

    side_combo_ = new QComboBox;
    side_combo_->addItems({tr("BUY"), tr("SELL"), tr("SHORT")});
    st_row->addWidget(side_combo_, 1);

    order_type_ = new QComboBox;
    order_type_->addItems({tr("MARKET"), tr("LIMIT"), tr("STOP")});
    st_row->addWidget(order_type_, 1);
    vl->addLayout(st_row);

    // Qty + Limit price row
    auto* qp_row = new QHBoxLayout;
    qp_row->setSpacing(6);

    qty_lbl_ = new QLabel(tr("QTY"));
    qp_row->addWidget(qty_lbl_);

    qty_input_ = new QLineEdit("10");
    qty_input_->setValidator(new QDoubleValidator(0, 1e9, 4, qty_input_));
    qp_row->addWidget(qty_input_, 1);

    price_lbl_ = new QLabel(tr("PRICE"));
    qp_row->addWidget(price_lbl_);

    price_input_ = new QLineEdit;
    price_input_->setPlaceholderText(tr("market"));
    qp_row->addWidget(price_input_, 1);
    vl->addLayout(qp_row);

    // Estimated total
    est_total_ = new QLabel(tr("EST. TOTAL  --"));
    vl->addWidget(est_total_);

    // Submit button
    submit_btn_ = new QPushButton(tr("PLACE ORDER"));
    submit_btn_->setFixedHeight(32);
    vl->addWidget(submit_btn_);

    // ── Accessibility ──
    symbol_input_->setAccessibleName(tr("Symbol"));
    lookup_btn_->setAccessibleName(tr("Look up symbol"));
    side_combo_->setAccessibleName(tr("Order side"));
    order_type_->setAccessibleName(tr("Order type"));
    qty_input_->setAccessibleName(tr("Quantity"));
    price_input_->setAccessibleName(tr("Limit / stop price"));
    submit_btn_->setAccessibleName(tr("Place order"));
    setTabOrder(symbol_input_, lookup_btn_);
    setTabOrder(lookup_btn_, side_combo_);
    setTabOrder(side_combo_, order_type_);
    setTabOrder(order_type_, qty_input_);
    setTabOrder(qty_input_, price_input_);
    setTabOrder(price_input_, submit_btn_);

    // ── Connections ──
    connect(lookup_btn_, &QPushButton::clicked, this, &QuickTradeWidget::lookup_symbol);
    connect(symbol_input_, &QLineEdit::returnPressed, this, &QuickTradeWidget::lookup_symbol);
    connect(side_combo_, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &QuickTradeWidget::on_side_changed);
    connect(submit_btn_, &QPushButton::clicked, this, &QuickTradeWidget::submit_order);
    connect(order_type_, QOverload<int>::of(&QComboBox::currentIndexChanged), this, [this](int idx) {
        price_input_->setEnabled(idx != 0); // disable for MARKET
        price_input_->setPlaceholderText(idx == 0 ? tr("market") : QStringLiteral("0.00"));
    });
    connect(qty_input_, &QLineEdit::textChanged, this, [this](const QString&) {
        if (current_price_ > 0) {
            double qty = qty_input_->text().toDouble();
            double total = qty * current_price_;
            est_total_->setText(tr("EST. TOTAL  $%1").arg(total, 0, 'f', 2));
        }
    });
    connect(this, &BaseWidget::refresh_requested, this, &QuickTradeWidget::lookup_symbol);

    apply_styles();

    // Initial lookup
    set_loading(true);
    // Hub path: initial lookup happens from showEvent.
}

void QuickTradeWidget::showEvent(QShowEvent* e) {
    BaseWidget::showEvent(e);
    if (!hub_active_)
        lookup_symbol();
}

void QuickTradeWidget::hideEvent(QHideEvent* e) {
    BaseWidget::hideEvent(e);
    if (hub_active_)
        hub_unsubscribe_all();
}

void QuickTradeWidget::apply_styles() {
    symbol_input_->setStyleSheet(input_style());
    lookup_btn_->setStyleSheet(QString("QPushButton { background: %1; color: %2; border: 1px solid %3; "
                                       "font-size: 10px; font-weight: bold; padding: 4px 10px; }"
                                       "QPushButton:hover { background: %4; }")
                                   .arg(ui::colors::BG_RAISED())
                                   .arg(ui::colors::AMBER())
                                   .arg(ui::colors::AMBER())
                                   .arg(ui::colors::BG_HOVER()));

    quote_card_->setStyleSheet(QString("background: %1; border-radius: 2px;").arg(ui::colors::BG_RAISED()));
    sym_label_->setStyleSheet(QString("color: %1; font-size: 14px; font-weight: bold; background: transparent;")
                                  .arg(ui::colors::TEXT_PRIMARY()));
    change_label_->setStyleSheet(
        QString("color: %1; font-size: 10px; background: transparent;").arg(ui::colors::TEXT_TERTIARY()));
    price_label_->setStyleSheet(QString("color: %1; font-size: 20px; font-weight: bold; background: transparent;")
                                    .arg(ui::colors::TEXT_PRIMARY()));
    bid_label_->setStyleSheet(
        QString("color: %1; font-size: 9px; background: transparent;").arg(ui::colors::POSITIVE()));
    ask_label_->setStyleSheet(
        QString("color: %1; font-size: 9px; background: transparent;").arg(ui::colors::NEGATIVE()));

    separator_->setStyleSheet(QString("background: %1;").arg(ui::colors::BORDER_DIM()));

    side_combo_->setStyleSheet(combo_style());
    order_type_->setStyleSheet(combo_style());

    qty_lbl_->setStyleSheet(
        QString("color: %1; font-size: 9px; background: transparent;").arg(ui::colors::TEXT_TERTIARY()));
    qty_input_->setStyleSheet(input_style());
    price_lbl_->setStyleSheet(
        QString("color: %1; font-size: 9px; background: transparent;").arg(ui::colors::TEXT_TERTIARY()));
    price_input_->setStyleSheet(input_style(ui::colors::BORDER_DIM()));

    est_total_->setStyleSheet(
        QString("color: %1; font-size: 10px; background: transparent;").arg(ui::colors::TEXT_SECONDARY()));

    // Submit button color depends on current side selection
    on_side_changed(side_combo_->currentIndex());
}

void QuickTradeWidget::on_theme_changed() {
    apply_styles();
}

void QuickTradeWidget::lookup_symbol() {
    QString sym = symbol_input_->text().trimmed().toUpper();
    if (sym.isEmpty()) {
        set_loading(false);
        return;
    }

    current_symbol_ = sym;
    auto& hub = datahub::DataHub::instance();
    // Swap subscription to the new symbol; drop the old one first.
    hub.unsubscribe(this);
    const QString topic = QStringLiteral("market:quote:") + sym;
    hub.subscribe(this, topic, [this](const QVariant& v) {
        if (!v.canConvert<services::QuoteData>())
            return;
        set_loading(false);
        apply_quote(v.value<services::QuoteData>());
    });
    // Kick a fresh fetch so the card updates immediately even if the
    // cached TTL hasn't expired.
    hub.request(topic);
    hub_active_ = true;
    set_loading(true);
}

void QuickTradeWidget::apply_quote(const services::QuoteData& q) {
    current_price_ = q.price;
    current_symbol_ = q.symbol.isEmpty() ? current_symbol_ : q.symbol;

    sym_label_->setText(current_symbol_);
    price_label_->setText(QString("$%1").arg(q.price, 0, 'f', 2));

    double chg = q.change_pct;
    QString chg_str = QString("%1%2%").arg(chg >= 0 ? "▲ +" : "▼ ").arg(chg, 0, 'f', 2);
    QString chg_col = chg > 0   ? ui::colors::POSITIVE()
                      : chg < 0 ? ui::colors::NEGATIVE()
                                : ui::colors::TEXT_SECONDARY();
    change_label_->setText(chg_str);
    change_label_->setStyleSheet(QString("color: %1; font-size: 10px; background: transparent;").arg(chg_col));

    // QuoteData from yfinance has no bid/ask — show em-dashes rather than
    // a fabricated spread (the previous price*0.0005 placeholder was
    // misleading on a trade-entry widget). Real bid/ask must come from a
    // broker quote stream (`broker:<id>:<account>:quote:<sym>`) which the
    // user wires up via the gear-icon config — wiring deferred.
    bid_label_->setText(tr("BID  —"));
    ask_label_->setText(tr("ASK  —"));

    double qty = qty_input_->text().toDouble();
    if (qty > 0)
        est_total_->setText(tr("EST. TOTAL  $%1").arg(qty * q.price, 0, 'f', 2));
}

void QuickTradeWidget::hub_unsubscribe_all() {
    datahub::DataHub::instance().unsubscribe(this);
    hub_active_ = false;
}

void QuickTradeWidget::on_side_changed(int idx) {
    // BUY = green, SELL/SHORT = red
    QString color = (idx == 0) ? ui::colors::POSITIVE() : ui::colors::NEGATIVE();
    submit_btn_->setText(idx == 0   ? tr("PLACE BUY ORDER")
                         : idx == 1 ? tr("PLACE SELL ORDER")
                                    : tr("PLACE SHORT ORDER"));
    submit_btn_->setStyleSheet(QString("QPushButton { background: %1; color: %3; border: none; "
                                       "font-size: 11px; font-weight: bold; }"
                                       "QPushButton:hover { background: %2; }")
                                   .arg(color, color, ui::colors::TEXT_PRIMARY()));
}

void QuickTradeWidget::submit_order() {
    QString sym = current_symbol_.isEmpty() ? symbol_input_->text().trimmed().toUpper() : current_symbol_;
    double qty = qty_input_->text().toDouble();
    QString side = side_combo_->currentText();

    if (sym.isEmpty() || qty <= 0) {
        QMessageBox::warning(this, tr("Quick Trade"), tr("Please enter a valid symbol and quantity."));
        return;
    }

    // NOTE: the removed `price_str` local compared `order_type_->currentText()`
    // against the literal "MARKET" — a translated string, so the branch was
    // wrong in every non-English locale. It was also immediately Q_UNUSED'd.
    //
    // This dashboard widget has no broker/account binding, so it cannot place a
    // real or paper order. Previously it popped an "Order sent to trading
    // engine" success box while sending nothing — a dangerous false confirmation
    // on a trading terminal. Be honest and point the user at the real order
    // entry (Equity/Crypto Trading), which has account selection, paper/live
    // routing and an explicit confirmation. (Wiring Quick Trade to an account is
    // tracked as a follow-up.)
    QMessageBox::information(
        this, tr("Quick Trade"),
        tr("Quick Trade is a preview widget and is not connected to a trading account — no order was placed.\n\n"
           "To place %1 %2 %3, use the Equity Trading or Crypto Trading screen, which routes the order to your "
           "selected broker/paper account with confirmation.")
            .arg(side)
            .arg(qty, 0, 'f', 0)
            .arg(sym));
}

void QuickTradeWidget::retranslateUi() {
    BaseWidget::retranslateUi();
    set_title(tr("QUICK TRADE"));
    if (lookup_btn_)
        lookup_btn_->setText(tr("LOOKUP"));
    if (qty_lbl_)
        qty_lbl_->setText(tr("QTY"));
    if (price_lbl_)
        price_lbl_->setText(tr("PRICE"));
    if (symbol_input_)
        symbol_input_->setPlaceholderText(tr("Symbol (e.g. AAPL)"));
    // Combo items and the bid/ask/total labels were previously left in the old
    // language after a live switch.
    if (order_type_) {
        const int cur = order_type_->currentIndex();
        const QStringList items = {tr("MARKET"), tr("LIMIT"), tr("STOP")};
        for (int i = 0; i < order_type_->count() && i < items.size(); ++i)
            order_type_->setItemText(i, items[i]);
        order_type_->setCurrentIndex(cur);
        if (price_input_)
            price_input_->setPlaceholderText(cur == 0 ? tr("market") : QStringLiteral("0.00"));
    }
    if (side_combo_) {
        const int cur = side_combo_->currentIndex();
        const QStringList items = {tr("BUY"), tr("SELL"), tr("SHORT")};
        for (int i = 0; i < side_combo_->count() && i < items.size(); ++i)
            side_combo_->setItemText(i, items[i]);
        side_combo_->setCurrentIndex(cur);
    }
    if (bid_label_)
        bid_label_->setText(current_price_ > 0 ? tr("BID  —") : tr("BID --"));
    if (ask_label_)
        ask_label_->setText(current_price_ > 0 ? tr("ASK  —") : tr("ASK --"));
    if (est_total_) {
        const double qty = qty_input_ ? qty_input_->text().toDouble() : 0.0;
        est_total_->setText(current_price_ > 0 && qty > 0 ? tr("EST. TOTAL  $%1").arg(qty * current_price_, 0, 'f', 2)
                                                          : tr("EST. TOTAL  --"));
    }
    // submit_btn_ text is side-aware ("PLACE BUY ORDER" etc.) — let on_side_changed re-derive it.
    if (side_combo_)
        on_side_changed(side_combo_->currentIndex());
}

} // namespace fincept::screens::widgets